1. Field of the Invention
The subject invention relates to intravascular catheters, and more particularly, to a guided intravascular catheter sheath having a bi-directional steering assembly for accurately placing the distal end of the sheath at a targeted location in a patient's body, to facilitate the introduction of a diagnostic and/or therapeutic device to the targeted location.
2. Description of Related Art
There are many instances where physicians must introduce diagnostic and therapeutic devices into the body, such as diagnostic and therapeutic electrodes, ultrasound transducers and other surgical tools. The diagnostic and therapeutic devices are often carried by catheters, which allow physicians to gain access to the body in a minimally invasive manner by way of bodily lumens. In cardiac treatment, for example, a catheter is advanced through a main vein or artery into the region of the heart that is to be treated.
One method of introducing diagnostic and therapeutic devices into the body is to introduce a tubular member (typically a “sheath”) into the vicinity of the targeted region. A diagnostic or therapeutic device is then passed through the sheath to the targeted region. If necessary, the diagnostic or therapeutic apparatus may be removed after its function is performed, but the sheath can be left in place, so that other devices can be advanced to the targeted region to complete the diagnostic and/or therapeutic procedure.
Precise placement of the diagnostic or therapeutic devices is very important, especially in those procedures concerning the heart. To that end, some conventional sheaths are guided to the targeted region with a steerable catheter that is located within the sheath lumen. Once the sheath reaches the targeted region, the steerable catheter is removed from the sheath and a catheter carrying the diagnostic or therapeutic device is advanced through the lumen. This type of sheath lacks any onboard steering mechanism. As a result, redeployment of the distal portion of sheath, even to a region in close proximity to the initially targeted region, requires the withdrawal of the diagnostic or therapeutic apparatus and the reintroduction of the steering catheter.
Other sheaths include a steering mechanism that allows the physician to guide the distal portion of the sheath to the targeted region. An example of a highly maneuverable bidirectional steerable sheath is disclosed in commonly assigned U.S. Patent Application Publication 2015/0057610 to Osypka et al. While this device is well suited for the precise placement of diagnostic or therapeutic devices within a patient's body, the bi-directional steering mechanism associated therewith is relatively complex, having several cooperating structural components that are relatively difficult to manufacture and assemble at a low cost. Accordingly, there remains a need in the art for a steerable sheath with a bi-directional steering mechanism that is less complex, easy to use and more easily manufactured and assembled.